1. Field of the Invention
The present invention pertains to the operation of an electronically controlled medical device. More particularly, the invention pertains to enabling one or more operating features of an electronically controlled medical device during a trial period and allowing a user to continue using the one or more operating features on a subscription basis.
2. Description of the Related Art
A wide variety of electronically controlled medical devices are known and used to provide an equally wide variety of medical services ranging from monitoring the condition of a patient to providing a medical treatment. A common feature of electronically controlled medical devices is that a microprocessor executes an operating routine which enables any number of the device's operating features.
Many electronically controlled medical devices are specifically designed and manufactured such that their processors execute a single operating routine each and every time the device is used. For example, the processor in a conventional pulse oximeter executes an operating routine which enables the pulse oximeter to monitor a patient's arterial oxygen concentration. As another example, the processor in a conventional electroencephalograph executes an operating routine which enables the electroencephalograph to monitor a patient's brain waves. The operating features provided by each of these devices do not change because the operating routine executed by each processor does not change over the life of the device.
For purposes of the present invention, the phrase “operating feature” refers to any functional capability of the medical device. This includes features that are determined or set at the time of manufacture and cannot be altered by the user. This also includes features of the medical device that can be set, selected, or adjusted by an authorized technician, caregiver, and/or user, among others. Examples of operating features of specific medical devices are discussed in greater detail below.
It can be appreciated that the need may arise to alter the operating routine and/or to upgrade the operating routine of a medical device after the manufacturing process is completed. For example, an operating routine may need to be altered to correct an error and/or an operating routine may need to be upgraded to take advantage of the latest technological advances developed after the device was released. U.S. Patent Application Publication No. 2002/0077856 to Pawlikowski et al., the entire contents of which are incorporated herein by reference, teaches a method and system for altering/upgrading one such type of electronically controlled medical device, a positive pressure therapy device.
For purposes of the present invention, the phases, “positive pressure therapy device”, “therapy device”, “pressure support system”, and/or derivatives thereof, include any electronically controlled medical device or system, invasive or non-invasive, that delivers a flow of breathing gas to the airway of a patient (also referred to herein as a “user”). A positive pressure therapy device is typically used to treat a medical disorder, such as obstructive sleep apnea (OSA), congestive heart failure, and central sleep apnea, as well as other cardio-respiratory disorders. The positive pressure therapy device produces a flow of breathing gas at an elevated pressure which is delivered to a patient's airway via a patient circuit. The positive pressure therapy device may function in a number of modes, such as and without limitation, continuous positive airway pressure (CPAP) mode, bi-level pressure support mode, “auto-titration” mode, proportional assist ventilation (PAV) mode, and proportional positive airway pressure (PPAP) mode, each of which is discussed in more detail below.
The modes of operation, as well as the functions capable of being provided by the positive pressure therapy device in each mode, are typically determined at the time of manufacture. However, the specific mode in which the positive pressure therapy device is to selected to operate, the specific functions associated with the selected mode that are enabled, and the specific settings for a number of adjustable parameters of the selected mode are generally not set when the positive pressure therapy device leaves the factory. Instead, a dealer may select these items based on the needs of the user.
Some positive pressure therapy devices are manufactured to operate in a single pressure support mode. However, many conventional positive pressure therapy devices are manufactured with the capability of operating in multiple pressure support modes (such as, CPAP, bi-level, auto-titration, PPAP, PAV, or a combination thereof, among others). Accordingly, a manufacturer, supplier, or seller of medical devices is able to sell or lease a number of identical medical devices to a medical device provider or dealer. The medical device provider or dealer then enables and/or disables particular operating features of the medical devices prior to distributing the medical devices to the doctors' offices, hospitals, or directly to the users. For example, a manufacturer may produce a positive pressure therapy device capable of providing several pressure support modes (e.g., CPAP, bi-level, etc.). The dealer, upon receiving an order, can then enable the prescribed desired pressure support mode and the desired operating features associated with that mode and/or disable the un-prescribed pressure support mode and the operating features associated with those un-prescribed modes prior to distributing the device to the patient.
A dealer, for example, may have in stock from the manufacturer a positive pressure therapy device that is capable of providing CPAP, bi-level, and auto-titration modes of therapy. For a patient who is prescribed CPAP therapy as a treatment for OSA, the dealer enables the device to function in the CPAP mode prior to delivering the device. The other modes of therapy may are disabled. In this example, the CPAP mode may have a maximum pressure setting, a minimum pressure setting, a ramp time setting, and alarm settings (among other settings) associated therewith when shipped by the manufacturer to the dealer. The dealer, prior to delivering the device to the user, may enable only the maximum and minimum pressure settings and one or more alarm settings. The other alarm settings and the ramp time setting are disabled. The dealer may also set the device to deliver the supply of breathing gas to the user at the therapeutic level prescribed by the user's physician. The mode in which the positive pressure therapy device operates, the functions of the positive pressure therapy device associated with each mode, and the adjustable parameters associated with each mode are considered to be, without limitation, examples of the operating features of the positive pressure therapy device for present purposes.
In CPAP mode, the positive pressure therapy device supplies a flow of breathing gas at a constant positive pressure to the airway of a patient throughout the patient's breathing cycle. The ability of a positive pressure therapy device to provide a continuous pressure, as opposed, for example, to a variable pressure, is an operating feature of the system. The specific pressure at which the device is set to deliver the breathing gas (i.e., the therapeutic pressure) is another example of an operating feature of the system. Setting the therapeutic pressure is accomplished, for example, by manually setting a switch, dial, knob or other input device associated with the medical device.
For bi-level pressure support mode, the pressure of the breathing gas delivered to the patient varies in synchronization with the patient's breathing cycle. Generally, a lower pressure is delivered to the patient during the expiratory phase of the breathing cycle than is delivered during the inspiratory phase. As a result, the patient receives the necessary pressure support during inspiration to treat their disorder, such as OSA, but is not breathing out against a relatively high pressure during expiration. Bi-level pressure support provides increased comfort to some patients. With bi-level pressure support, the patient's inspiratory positive airway pressure (IPAP), expiratory positive airway pressure (EPAP), and how the device detects and compensates for system leaks, if any, are examples of operating features of the positive pressure therapy device. Bi-level pressure support is taught, for example, in U.S. Pat. No. 5,148,802 to Sanders et al., U.S. Pat. No. 5,313,937 to Zdrojkowski et al., U.S. Pat. No. 5,433,193 to Sanders et al., U.S. Pat. No. 5,632,269 to Zdrojkowski et al., U.S. Pat. No. 5,803,065 to Zdrojkowski et al., and U.S. Pat. No. 6,029,664 to Zdrojkowski et al., the entire contents of which are incorporated by reference into the present invention.
For auto-titration mode the pressure provided to the patient changes based on the detected conditions of the patient, such as whether the patient is snoring or experiencing an apnea, hypopnea, upper airway resistance, or a combination thereof. In this mode, the positive pressure therapy device itself determines the optimum pressure to deliver the flow of gas to the patient. If snoring or an apnea is detected, for example, the positive pressure therapy device increases the pressure of the gas delivered to the patient's airway. When the detected snoring or apnea ceases, the positive pressure therapy device decreases the pressure of the gas delivered to the patient's airway. With auto-titration mode, the operating features typically include, for example and without limitation, a maximum and/or minimum pressure that can be output by the device and the technique by which the system alters the patient pressure.
An example of an auto-titration positive pressure therapy device that adjusts the pressure delivered to the patient based on whether or not the patient is snoring is the Virtuoso® CPAP family of devices manufactured and distributed by Respironics, Inc. This auto-titration pressure support mode is taught in U.S. Pat. Nos. 5,203,343; 5,458,137 and 6,087,747 all to Axe et al., the entire contents of which are incorporated herein by reference. An example of a positive pressure therapy device that actively tests the patient's airway to determine whether obstruction, complete or partial, could occur and adjusts the pressure output to avoid this result is the Tranquility® Auto CPAP device, also manufactured and distributed by Respironics, Inc. This auto-titration pressure support mode is taught in U.S. Pat. No. 5,645,053 to Remmers et al., the entire content of which is incorporated herein by reference.
For PAV mode, the pressure of gas delivered to the patient varies with the patient's breathing effort to increase patient comfort. U.S. Pat. Nos. 5,044,362 and 5,107,830 both to Younes, the entire contents of which are incorporated herein by reference, teach a positive pressure therapy device capable of operating in a PAV mode. For PPAP mode, breathing gas is delivered to the user based on the flow generated by the user. U.S. Pat. Nos. 5,535,738; 5,794,615; and 6,105,573 all to Estes et al., the entire contents of which are incorporated herein by reference, teach a positive pressure therapy device capable of operating in a PPAP mode. The percentage of assistance provided by the device is at least one of the operating features of a positive pressure therapy device operating in the PAV or PPAP modes.
Other operating features for a positive pressure therapy device include, without limitation, alarm features, time backup breath features (a ventilatory breath delivered when a user fails to spontaneously initiate a breath within a set period of time), and a pressure ramp (the pressure level provided to the user is gradually increased over time). Activating, deactivating, or altering most features of the positive pressure therapy device is preferably and, in many cases, necessarily done by an authorized caregiver or technician under the direction and/or supervision of the physician or other caregiver responsible for that user.
In certain situations, medical reimbursement policies dictate that a patient be treated with the most basic operating features of a first type of pressure support mode before a reimbursement will be authorized for more advanced features of that type of pressure support mode and/or authorized for a second type of pressure support mode. For example, it is not uncommon for an OSA sufferer to initially be prescribed treatment with a CPAP device. The patient may then be switched to a bi-level device only after it is determined that CPAP therapy does not provide the desired therapy results. Under current reimbursement policies, a dealer only receives reimbursement for providing a CPAP device with the basic operating features enable. Thus, these reimbursement policies create a disincentive for the dealer to enable more advanced, un-prescribed operating features.
Because a patient only receives a device capable of providing the basic operating features associated with the prescribed pressure support mode, the patient may never experience the benefits related to more advanced operating features of that mode or the benefits related to operating features of a different pressure support mode. As a result, a patient finding their prescribed pressure support mode uncomfortable or ineffective may fail to comply with their prescribed therapy regimen. In many cases, patients are unaware that more advanced operating features or different pressure support modes even exist. Thus, such patients may never experience more advanced operating features or a different therapy even though these may provide a more comfortable and more effective treatment regiment to the patient.
Even if aware of the benefits of the more advanced operating features or other therapy mode, a patient may experience difficulty in having their device upgraded. For example, the patient may be required to return their device to the dealer or manufacturer to complete the upgrade. Additionally, the dealer may be reluctant to upgrade the device because of the disincentives created by the reimbursement policies.
Accordingly, a need exists for an improved system and method for providing a patient with the opportunity to experience a number of additional operating features of a medical device on a trial basis and for providing the patient the opportunity to upgrade his or her device with the additional operating features if so desired.